Cloud cost visibility that runs on your machine.
No servers, no SaaS fees, no third-party data sharing.
Download · Get Started · Features
CostGoblin is a desktop app that syncs your AWS billing data locally and queries it with DuckDB. Filter, drill down, and slice costs by any dimension — from a plane at 10,000 meters.
Download the latest release for your platform from costgoblin.com. macOS binaries are signed and notarized. See the code signing policy for details.
The app auto-updates when a new version is available.
npm install
make devOn first launch, the setup wizard guides you through connecting to your AWS CUR data.
- Node.js 20+
- AWS CUR 2.0 report exported as Parquet to S3
CostGoblin reads CUR 2.0 via AWS Data Exports (not legacy CUR). Create one in the AWS Billing Console → Data Exports.
Export settings:
| Setting | Value |
|---|---|
| Export type | Standard data export (table: COST_AND_USAGE_REPORT) |
| Time granularity | Daily |
| Format | Parquet |
| Compression | Snappy |
| Overwrite | Overwrite existing data export file |
CUR 2.0 Data Exports does not have "Include resource IDs" / "Include net columns" checkboxes — those are legacy CUR. In Data Exports you pick the columns explicitly in the SQL editor (see below).
Paste this into the SQL query field when creating the export. It's the full set of columns CostGoblin can read — extras you don't paste become inline "Degraded" warnings in Cost Scope but never break queries.
SELECT
-- Required: app won't function without these
line_item_usage_start_date,
line_item_usage_account_id,
line_item_usage_account_name,
line_item_line_item_type,
line_item_line_item_description,
line_item_operation,
line_item_usage_type,
line_item_usage_amount,
line_item_resource_id,
line_item_unblended_cost,
product_servicecode,
product_product_family,
product_region_code,
resource_tags,
-- Recommended: each unlocks one metric option in Cost Scope
pricing_public_on_demand_cost, -- "On-demand list price" metric
reservation_effective_cost, -- "Amortized" metric (RI portion)
savings_plan_savings_plan_effective_cost, -- "Amortized" metric (SP portion)
-- Optional: enables the "Net" perspective (credits/refunds applied)
line_item_net_unblended_cost,
reservation_net_effective_cost,
savings_plan_net_savings_plan_effective_cost
FROM COST_AND_USAGE_REPORTThe doubled prefix on
savings_plan_savings_plan_effective_costis AWS's snake_case conversion ofsavingsPlan/SavingsPlanEffectiveCost— not a typo. Same for the_net_variant.
Why no
line_item_blended_cost? CostGoblin intentionally doesn't ship AWS's "Blended" metric. It was designed to distribute classic RI discounts fairly across linked accounts when commitments sat in a central payer account — but AWS never extended the math to Savings Plans, and SPs are how virtually all modern fleets buy commitment-based discounts. On an SP-based fleet, Blended is nearly indistinguishable from Unblended and provides none of the chargeback fairness it was originally invented for. We use Amortized for chargeback (it spreads SP/RI fees correctly across covered usage) and On-demand list price for fair per-team cost views when commitment allocation is uneven. If your config still hascostMetric: "blended"it's silently migrated toamortizedat load time. Skipping this column also keeps your CUR export lighter.
| Tier | If you skip these |
|---|---|
| Required | App won't ingest the export at all |
| Recommended | The matching metric in Cost Scope shows "Degraded — falls back to Unblended"; numbers are still correct under the Unblended metric |
| Optional (Net) | The Net perspective toggle silently falls back to Gross |
The app probes your parquet schema once at startup and shows the warning inline next to each affected metric. Queries never error on a missing column — they fall through to the next available one.
CUR 2.0 exports are immutable, so you can't add columns to an existing export. Create a new one with the full SQL above, point it at a fresh S3 prefix, wait one billing cycle for the first partition to land, then update CostGoblin's S3 prefix in the setup wizard.
Reference: which column wires up which metric × perspective
For each metric / perspective combo, the app reads the first available column in priority order, falling back down the chain when a column isn't in the export:
| Selection | Reads from |
|---|---|
| Unblended · Gross | line_item_unblended_cost |
| Unblended · Net | line_item_net_unblended_cost → line_item_unblended_cost |
| Amortized · Gross | CASE on line_item_line_item_type: DiscountedUsage → reservation_effective_cost; SavingsPlanCoveredUsage → savings_plan_savings_plan_effective_cost; RI/SP fee rows → 0; everything else → line_item_unblended_cost |
| Amortized · Net | Same CASE, but using the _net_ variants of each column and line_item_net_unblended_cost as the fallback |
| On-demand list price | pricing_public_on_demand_cost → line_item_unblended_cost |
The Amortized expression uses a CASE on line_item_type rather than a plain COALESCE because AWS populates reservation_effective_cost and savings_plan_savings_plan_effective_cost with 0 (not NULL) for non-applicable rows — a COALESCE chain would silently zero out every Usage / Tax / Credit row.
The S3 export should look like:
s3://bucket/prefix/
data/
BILLING_PERIOD=YYYY-MM/
*.snappy.parquet
metadata/
BILLING_PERIOD=YYYY-MM/
manifest.json
CostGoblin reads profiles from ~/.aws/config and ~/.aws/credentials. The wizard lists available profiles and lets you pick one.
Using SSO:
The app has a built-in SSO login button — click it next to your profile and CostGoblin will launch aws sso login for you. Or run it manually:
aws configure sso
aws sso login --profile your-profile-nameWithout giving the app S3 access: Skip the wizard and download CUR data manually:
aws s3 sync s3://your-bucket/path/to/cur/ ~/Library/Application\ Support/@costgoblin/desktop/data/raw/Then use the Data tab to repartition the downloaded files.
- S3 billing sync — downloads CUR parquet files into daily Hive partitions
- Interactive dashboard — pie charts, stacked bar charts, treemaps, and more, with drill-down into any dimension
- Trends — period-over-period comparison with bubble chart visualization, filterable by dimension with configurable thresholds
- Findings — surfaces AWS cost optimization recommendations (rightsize, delete unused, purchase SPs/RIs) with effort estimates and savings projections
- Missing Tags — identifies untagged resources by taggability, with Slack/Jira copy and CSV export
- Explorer — browse raw line items with configurable columns, filters, and sorting
- Filter by any dimension — account, service, region, team, product, environment, or custom tags
- Custom dimensions — map any AWS tag to a first-class cost allocation dimension
- Tag normalization — aliases applied at query time, fix messy tags without re-processing
- Composable views — drag-and-drop widget builder with 9 widget types (pie, bar, stacked bar, line, treemap, heatmap, bubble, table, summary)
- Cost Scope — configure cost metrics (amortized, on-demand list price, unblended) and exclusion rules
- Vault encryption — optional AES-256-GCM at-rest encryption for local billing data, with system keychain integration
- MCP server — Model Context Protocol integration for querying cost data from AI assistants
- Dark/light mode — theme toggle with two chart color palettes (standard + Okabe-Ito colorblind-safe)
- Auto-updates — the app checks for new versions on startup and installs them automatically
- CSV export — export any view for reporting
- Works offline — once synced, no internet needed
packages/
core/ @costgoblin/core — DuckDB queries, S3 sync, config (no framework deps)
ui/ @costgoblin/ui — React components (visx charts, Tailwind, shadcn/ui)
desktop/ Electron shell — imports core and ui
mcp/ @costgoblin/mcp — Model Context Protocol server for AI assistant integration
- DuckDB for analytical queries over local Parquet files
- Electron for cross-platform desktop app
- React 19 + visx (D3 primitives as React components) for charts
- Tailwind CSS v4 for styling
make help # show available commands
make dev # launch Electron in dev mode
make test # run vitest
make lint # run tsc + eslint
make reset # wipe app data, restart with wizardCostGoblin is licensed under the GNU Affero General Public License v3.0 only (AGPL-3.0-only). See LICENSE for the full text.
In short:
- You can use, modify, and redistribute CostGoblin freely.
- If you distribute modified versions, or make them available over a network (e.g. host a fork as a service), you must publish your modifications under the same license.
- Commercial use is permitted; what the AGPL prevents is closed-source forks and undisclosed SaaS re-hosting.
If you want to embed CostGoblin in a closed-source product or ship it under different terms, a commercial license is available on request — contact the author.
